1. Field of the Invention
The present invention relates to a testing assembly, and more particularly, to a testing assembly for an electrical test of an electronic package.
2. Description of the Related Art
After the integrated circuit (IC) chip had been packaged into an electronic package, a component test is usually performed on the testing assembly to ensure the quality of the package by identifying the characteristic parameters of the package. In addition, in order to ensure that the package operates normally in a computer system after installed into the computer system, a system test is further performed on the package, and it is a necessary process for the package of high-end or high-cost IC chip.
However, various testing assemblies should be designed with respect to the different types of the packages. Regarding the package of the Ball Grid Array (BGA) type, the testing assembly comprises a testing circuit board and a testing socket mounted thereon. The testing socket comprises an insulating body and a plurality of pogo-pins, wherein the pogo-pins pass through the insulating body, and the arrangement of the pogo-pins corresponds to the disposition of the spherical contacts of the BGA package to be tested. In addition, a part of the surface of the testing circuit board contains a plurality of testing pads, and each testing pad is corresponding to one pogo-pin of the testing socket. Thus, the bottom of the pogo-pins elastically contact with the testing pads respectively.
When the BGA package is mounted on the testing socket and the contact surface of the BGA package contact with the holding surface of the insulating body, the top of the pogo-pins contact with the spherical contacts on the contact surface of the BGA package respectively, such that the pogo-pins are configured as the electric channels between the spherical contacts of the BGA package and the testing pads of the testing circuit board respectively. Accordingly, the BGA package is electrically coupled to the testing circuit board via the testing socket, such that the electrical test can be performed on the IC chip inside the BGA package.
However, compared with the conducting trace of the BGA package and/or the conducting trace of the testing circuit board, the impedance of the pogo-pins on the testing socket is rather low, thus causing the impedance mismatch in the entire signal transmission path, and reducing the return loss of the signal transmission. This significantly deteriorates the testing accuracy of the testing assembly.